In the field of model railroadry, it is desirable to add features and functions to enhance the basic process of a train running around the length of a track. As a result, model railroad manufacturers have spent considerable time and effort to develop methods and apparatus, both mechanical and electrical, that offer extra features which appeal to the senses of sight and sound as well as functions which create operational features similar to that of real trains. There are several features in particular that have been the focus of much research, development and design in the model train industry. Some of the most notable developments involve apparatus emitting train sounds, units producing smoke or steam effects and various methods of coupling and uncoupling train cars.
A magnet or an electromagnet has been utilized in inventions related to model railroads. In particular, coupling and uncoupling devices often include utilization of a magnet or electromagnet to create a movement of the train car couplers, either by magnetic attraction or repulsion, to result in the coupling (joining) of two train cars or the uncoupling (separation) of two train cars. U.S. Pat. No. 2,223,905 to Beyer et al. uses an electromagnet located in a track section. This design, as well as similar inventions, requires an armature for the electromagnet projected as a lever from the track section to mechanically contact and uncouple the train car coupling members. These mechanical devices must be located and arranged in a very precise manner.
In other coupling and uncoupling designs, such as U.S. Pat. No. 3,069,023 to Ross, magnetic attraction provides the mechanism for uncoupling the coupler members by positioning magnets at predetermined locations of a track section. When a train car is appropriately positioned in conjunction with the magnets, sections of the couplers move out of the coupled position as a result of attraction to the magnet. In U.S. Pat. No. 5,775,525 to Brill, magnetic attraction utilizes a direct physical contacting of the magnets located on each of the train car coupling assemblies. Conversely, other designs, such as U.S. Pat. No. 3,840,127 to Edwards et al., implement magnetic repulsion to push away or deflect the coupler members in order to achieve separation of the train cars.
Model train enthusiasts seek out and enjoy features and decorations of train cars that add an element of novelty and uniqueness to their train layouts, but at the same time, they desire an adherence to the prototypical look and function. For instance, most model train operators would consider a model train sound system which had a recording of a real train preferable to one with a mechanically produced imitation sound. Although highly entertaining, these additional features often require expensive accessories for operation.
U.S. Pat. No. 4,369,943 to Husein presents an interesting combination of operational accessories that replicates conditions at a train gate crossing. A detector circuit uses two pairs of magnetically-operated relays positioned beneath the tracks of a grade crossing and a separate single pair of magnetically-operated relays located at the grade crossing. A locomotive with a permanent magnet triggers the two pairs of relays as it passes the grade crossing and activates the coil relays to operate the lowering of the crossing gate, flashing lights and sounding bells. Then, as a train car with a permanent magnet for operating the single pair grade crossing relays passes the grade crossing, the gate raises and the lights and bells are deactivated. One disadvantage in this design, as well in other similar designs, is that the relays must be triggered every time the train with the magnet passes.
Presently, it is reasonable and expected by users to operate these cars anywhere on the track with signaling transmitted by radio control or by infrared. Cars which operate by radio control or infrared must be outfitted with roller pick ups such that the track voltage can be used anywhere on the track. Specific remote controls are also required. Activated by a remote control, a control system shown in U.S. Pat. No. 5,441,223 to Young et al. sends encoded commands to a receiver and, in the process, generates an electromagnetic field which extends several inches about the track to activate the receiver in the train car. This system involves a complex system of command controlled functions that utilizes the specifically designed remote control.
In the field of model trains, track sections often have three rails with current running through the middle rail and two grounded outer rails. Conventionally, power is sent to the car through a special section of track that adds two additional rails. The additional rails are centered between the middle rail and the two outer rails. Voltage is transmitted to the car through pickup shoes, or slide shoes, attached to the train car and aligned with the two additional rails. Not only does this design require the use of a five rail track section which does not look prototypical, but pickup shoes are required on the train car in order for it to operate. The presence of these shoes on the bottom of the train car also adds an extra, non-prototypical looking part to the train and creates the problem of the shoes dragging or catching as the cars go around the track. Even if a model train operator desires to use such a train car only infrequently, the five-rail track and the pickup shoes are always present.